Abstract: The initial structural strength of soil is a core parameter for ensuring engineering stability.Conventional shear strength indices and pre-consolidation pressure often fail to accurately capture the cementation characteristics and complex stress responses inherent to structured soils, leading to challenges in assessing the in-situ structure of soil masses in engineering practice.This study proposed the critical load P_y to characterize this initial structural strength.Void ratio-pressure data were acquired through confined compression tests.The compression curve was fitted using models such as polynomial functions, and the critical state point was identified via curvature analysis.P_y was subsequently determined by solving a system of equations.The method was applied to a water diversion project in Jilin Province, and the results demonstrated a difference of up to 40% in P_y values between natural and saturated silty clay, highlighting the influence of water content on inter-particle bonding forces.Furthermore, the numerical method presented demonstrated higher accuracy compared to traditional approaches.This methodology effectively reflected the in-situ bearing capacity of soil, provided theoretical support for the engineering design of structured soils like soft clay, and enhanced accuracy in foundation stability assessments and reduced engineering safety risks.